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[AmigaBruno]

I'm trying once more to get into electronics, meaning building as well as repairing things. During my research I've been surprised by the kind of components and projects that are available, although they seem to be obsolete technology, far older than classic Amigas. These projects include a crystal radio set and a Pong game console. Apart from these, people are able to get hold of components to make Sinclair Spectrum clones. These clones use compatible components, but now there's also an FPGA Spectrum clone. I know that various computers used graphics chips that had the same resolution (256x192?) as the Sinclair Spectrum.

Bearing all of this in mind, I can't understand the problems people are having getting hold of or making projects which are compatible with classic Amigas. I've now more or less given up on trying to get a hard drive which would fit my Amiga A500 Plus. It seems that not even Iomega Zip drives are compatible without a special interface. Surely, with enough electronics knowledge it should be possible to build a new Amiga hard drive controller and interface, as well as monitors which are compatible with classic Amigas without using a scandoubler or flicker fixer. Please will someone tell me what problems there would be doing either or these things?

BTW, later today I'll be going to an event where they do repairs, so I hope I'll find out some of this information there, but it won't be about the classic Amiga.

[ral-clan]

The crystal radio you mentioned above is an analogue electronic project.

Digital projects can be more difficult to do.

If the PONG project IS a digital one, instead of analogue, then it requires one of those AY Pong on a chip IC's which really make it a lot easier for you to do the project - as essentially all the work has been done by the IC manufacturer. Try and make a pong console only using individual transistors, etc. from scratch and see how easy that is.

I'm not sure about the Sinclair project, obviously it's digital but I haven't seen the descriptions - if it's simply a "kit" you order and assemble, then a lot of the hard work might already have been done (i.e. EPROM programming).

Usually these kind of home brew kits deal with technology that is several decades old --- it takes a while for the home hobby scene to catch up with technology. I.e. we are only now able to do 1980s / 90s computers in FPGA several decades later. There's nothing wrong with that but that's what it takes for the knowledge and equipment to trickle down to the home level.

Besides, have you looked in Aminet's "hacks" sections? I think I remember seeing do - it - yourself hard-drive controller instructions there.

But I think you overestimate how easy these projects are (i.e. they are harder than you think unless you have training and experience).

I don't know why you are having such trouble getting a hard drive for you Amiga 500+, try searching eBay or Amibay for "amiga sidecar" or "a500 hard drive" or go on amikit or vesalia. There are solutions.

http://www.students.tut.fi/~leinone3/ide/
http://www.amibay.com/showthread.php?t=37843

[ChuckT]

Originally Posted by AmigaBruno

Bearing all of this in mind, I can't understand the problems people are having getting hold of or making projects which are compatible with classic Amigas.

Bruno,

I've spent years surveying parts that could be used to make a single board computer. I could point you in the direction you want to go. You might want to visit anycpu.org and chat with us.

People who want to make a computer or a complex machine with chips don't always know what is involved. Chips make what is hard simple and what you think is simple is sometimes hard. Sometimes it isn't just about connecting the wires but it is about physics.

The problem is that manufacturers aren't going to make a part unless there is a market because products that don't sell means the manufacturer loses money. Warehouses are afraid to stock a part unless it sells and they lose money when the customer changes his or her mind.

A lot of times you have to be an engineer to read a datasheet for a chip. The datasheet for the processor in the Beaglebone is 2500+ pages long. Some of the smaller chips have datasheets that are at least 300 pages long. It takes some accomplished engineers a day to set up an ide.

Even people in the industry frown at the idea of making a single board computer because they know what it is like to make something and computers take many people to build. If you were to write BASIC in a month, do you think the language would be extremely buggy? Do you know anyone who can write a math package for a computer language? It takes expertise, finess and a lot of love, time, willpower, illumination and inspiration to make a computer.

If I haven't discouraged you, visit anycpu.org and come and talk with us.

Chuck

[paul1981]

Originally Posted by AmigaBruno

Bearing all of this in mind, I can't understand the problems people are having getting hold of or making projects which are compatible with classic Amigas. I've now more or less given up on trying to get a hard drive which would fit my Amiga A500 Plus. It seems that not even Iomega Zip drives are compatible without a special interface.

Kipper2k is making some good stuff for classics, including internal fastram expansions for A500 and A600 machines:
http://kipper2k.com/amigaforsale/

Check out MKL's IDE68K project, which enables internal IDE hard drive inside your A500:
http://www.students.tut.fi/~leinone3/ide/ide68k.html

[JimS]

Back in the Elder Days, I built a Z80 system from scratch... wire-wrapping all the boards... But I didn't design all of it, most of it came from plans in the hobbyist magazines of the time. (Kilobaud & Byte) But once I got it working, I kinda was scared off by realizing that I'd have to write an OS for it - or figure out how to port CP/M to it. So I went out and bought an Atari 800. ;-)

You should check out places like Sparkfun or Adafruit. They have a lot off cool chips already soldered to breakout boards so you don't have to deal with those teeny packages. I've been wishing for a Zorro board with multiple SPI ports that could drive a bunch of those boards...

[AmigaBruno]

Thanks for this information!

Sinclair Spectrum clones have been produced by various people over the years, a lot of them in the USSR before it was abolished, and since then in Russia, as well as other countries in what was called eastern Europe. They made them because they couldn't afford the real thing.

Here's the Pong console project I talked about http://www.mallinson-electrical.com/...mk121-pal.html . How advanced is that technology?

I managed to get one device out of three I took along to the repairs event brought back to life, although it's not working 100% yet. It was an ebook reader, where the charger turned out to be faulty. A old iPod couldn't be diagnosed, but there were some suggestions about getting a Creative Zen Vision: M player going again. Amazingly enough, there was even an Amiga enthusiast there who owns 3 Amiga A1200s and has offered to make a deal to sell me one at a price more reasonable than recent prices on eBay. He also told me that an Amiga SCSI controller would have to include some software or firmware.

[Castellen]

Originally Posted by AmigaBruno

Surely, with enough electronics knowledge it should be possible to build a new Amiga hard drive controller and interface, as well as monitors which are compatible with classic Amigas without using a scandoubler or flicker fixer. Please will someone tell me what problems there would be doing either or these things?

Yes, with enough knowledge, time and money you can do practically anything. The problem with the sorts of projects you mention, the knowledge required to do the job properly doesn't come overnight. As others have mentioned, to design a drive controller from scratch, you need to have a thorough understanding of the interface to the Amiga and to the drive in order to both design the controller hardware plus the software on the Amiga side. Then you need to look at physical construction, mounting, etc.

I've been electronics engineering for nearly 20 years and find it frequently annoying when people view any complex piece of electronics as something that can be whipped up by anyone holding a qualification to operate a light switch in five minutes by getting a few ICs and making a few random connections between them. Every good design is generally the result of years of experience and hundreds if not thousands of hours of development and testing.

I tend to favour older technology in new designs because it's often easier to work with and requires less design work as you can re-use proven circuit blocks from previous designs. e.g. 'modern' high speed logic can require complex design around signal propagation times, rise/fall times, PCB track lengths and more.

As an example, here's a design report from single board 8-bit embedded computer I designed from scratch a few years ago as an in-house universal production testing solution. Many of the individual blocks were copied from previous projects and designs with the intention of reducing development time and cost as much as possible. As a result the entire thing worked first time and met budget. But it still took weeks of hand made prototype blocks, calculations, writing hardware interface software and a basic operating system. See page 53 for how long it practically took and cost, and this is just a simple 8-bit embedded system reminiscent of what you'd see in the 1980s.

[ral-clan]

Originally Posted by AmigaBruno

Here's the Pong console project I talked about http://www.mallinson-electrical.com/...mk121-pal.html . How advanced is that technology?

That pong kit is more of an assembly project rather than an electronics project that would teach you anything about electronics or require you to figure out what components you need.

Hard to tell how "advanced" it is. Again - it looks like all the central logic is on that IC. Essentially a pong computer on a chip. Not really homebrew or anything. Fun though, if you like to learn how to solder components on a board.

I'm just guessing, but it's probably 1970s era technology in terms of how "advanced" it is.

[ChuckT]

Originally Posted by AmigaBruno

Here's the Pong console project I talked about http://www.mallinson-electrical.com/...mk121-pal.html . How advanced is that technology?

The Raspberry Pi can play pong and can also be used for different things.

The Pong console will be thrown away when it gets dirty, dusty and when you are bored with it. The pong console probably has a dedicated chip which can't be used for much else.

[ChuckT]

Originally Posted by Castellen

I've been electronics engineering for nearly 20 years and find it frequently annoying when people view any complex piece of electronics as something that can be whipped up by anyone holding a qualification to operate a light switch in five minutes by getting a few ICs and making a few random connections between them. Every good design is generally the result of years of experience and hundreds if not thousands of hours of development and testing.

I agree. The reason it looks easy is because someone spent years and hundreds or thousands of hours in development making something work.

[ChuckT]

Originally Posted by ral-clan

That pong kit is more of an assembly project rather than an electronics project that would teach you anything about electronics or require you to figure out what components you need.

I think the hardest part is making a vga ladder for video if you've never done video before.

HDMI is probably more involved and knowing where to get the licensed chips and components.

Writing an operating system to be in tune with everything operating on the computer would be a challenge as well.

[Iggy]

The problem with building new Amiga accessories is that the core of he system operates really slowly.
In the end, an FPGA re-implimentation is the only way to speed things up.

[ChaosLord]

Originally Posted by AmigaBruno

Bearing all of this in mind, I can't understand the problems people are having getting hold of or making projects which are compatible with classic Amigas. I've now more or less given up on trying to get a hard drive which would fit my Amiga A500 Plus. It seems that not even Iomega Zip drives are compatible without a special interface. Surely, with enough electronics knowledge it should be possible to build a new Amiga hard drive controller

I had a hard drive + 4MB ram expansion on my A500 in the 1989-1991 timeframe. They were produced by multiple manufacturers and many thousands were sold. Why didn't u buy one?

[freqmax]

Stuff were incredibly expensive back then?

[ChaosLord]

Originally Posted by freqmax

Stuff were incredibly expensive back then?

No it was super ridiculously cheap.

My A500 had 5 MEGABYTES of directly addressable ram + a hard drive.

My A2000 had 9 MEGABYTES of directly addressable ram + a ridiculous amount of HD storage.

And stereo DMA fed hardware double-buffered interrupt driven music.

And 32-bit multitasking.

Add up how much that cost to do on a Bill Gates compatible PC. Around $8 billion (google translation: IMPOSSIBLE in 1989)

Now any price I paid was fantastically cheap.